Security Identifier

A security identifier is like a name tag for things that you want to keep safe. Imagine you have a bunch of toys and you want to make sure nobody takes them without your permission. So you put a special sticker on each toy that has a unique name on it. This sticker is the security identifier.

Now, if anyone tries to take your toys, you can check the name tag and make sure it belongs to you. Similarly, in the grown-up world, things like stocks and bonds also have security identifiers to make sure they are kept safe and only traded by the right people. These identifiers might be numbers, letters, or other special codes that are unique to each security. So just like with your toys, the security identifier helps people keep track of who owns what and make sure everyone is following the rules.